1. Field of the Invention
The present invention concerns a lighting unit including devices for emitting a luminous flux in the direction of optical deflection devices for orienting the flux towards an outlet face of the unit. It more particularly concerns such a lighting unit further including a mask adapted to block a portion of the luminous flux, disposed between the emission devices and the optical deflection devices. These light emission devices are light sources.
2. Description of the Related Art
In lighting units of this type, the role of the mask is to block the unwanted rays of the luminous flux emitted by the emission devices in order for only a narrow and targeted beam to enter the optical deflection devices, so that on the one hand the rays are reflected correctly therein toward the outlet face of the unit and on the other hand no ray is reflected at adjoining walls delimiting these optical deflection devices.
It is clear that, for a given lighting unit, the position of the mask between the light emission devices and the optical deflection devices must be determined with precision and that the shape of the mask must be a function of the shape of the optical deflection devices, for the mask to be able to block the first rays deemed unwanted and to allow to pass the rays of the narrow beam directed towards the optical deflection devices. Particular attention is then paid to the machining of the mask and to the devices for positioning this mask relative to the light emission devices.
Moreover, the shape of the optical deflection devices varying from one vehicle to another, there is a provision for associating locating means with the lighting units to prevent the wrong mask being associated with the optical deflection devices, the effect of which would be either not to fulfill correctly the function of blocking unwanted rays or to block a portion of the flux correctly directed toward the optical deflection devices and therefore to limit the lighting efficacy of the lighting unit.